Analog Devices Inc./Maxim Integrated MAX6326XR31+T

Overview

MAX6326XR31+T from Maxim Integrated is an ultra-low-power, active-low push-pull microprocessor supervisory circuit designed to monitor 3.08V power supplies and assert a reset signal during brownout, power-up, and power-down events. It features a factory-trimmed 3.08V reset threshold (±1.5% at +25°C, ±2.5% over -40°C to +85°C), 100ms minimum reset timeout, 1µA max supply current at 3V, and operates down to 1.2V VCC. It is used in portable battery-powered systems requiring reliable, low-quiescent-power reset supervision.

For engineers reviewing the MAX6326XR31+T datasheet, MAX6326XR31+T pinout, MAX6326XR31+T application, or MAX6326XR31+T equivalent, key selection criteria include reset threshold accuracy, push-pull output drive capability, SC70-3 package compatibility, transient immunity, and guaranteed operation down to 1.2V VCC - all critical for embedded µP reset integrity in space-constrained, low-power designs.

Technical Context

The MAX6326XR31+T implements a precision bandgap-based reset comparator with built-in hysteresis (6.3mV) and internal timing capacitor to guarantee ≥100ms reset assertion after VCC rises above the 3.08V threshold. Its push-pull RESET output drives low (≤0.3V at 1.6mA) when asserted and high (≥0.8·VCC) when released, eliminating external pull-up components.

Designed for immunity to fast VCC transients, it ignores negative-going glitches shorter than ~100µs at 100mV overdrive and supports full operation across -40°C to +85°C. The device requires no external components, draws ≤1µA at 3V, and maintains valid reset state down to VCC = 1.2V - enabling robust supervision in deep-sleep and battery-depleted conditions.

Key Specifications

Pinout & Package

MAX6326XR31+T is housed in a 3-pin SC70-3 package (outline X3-2, land pattern 90-0208), with 0.65mm pitch, 0.9mm height, and RoHS-compliant lead-free construction (+T suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with MAX6326XR31+T, MAX809TR31+T trades 1.5µA higher quiescent current for broader second-source availability, while TPS3808G33DBVR offers TI's process stability but requires layout changes for open-drain support and accepts a 220mV higher reset threshold - impacting brownout sensitivity in 3.0V systems.

Availability

MAX6326XR31+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and smart meter communication units requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for MAX6326XR31+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6326 family was engineered specifically for ultra-low-power microprocessor reset supervision in battery-critical and space-constrained systems, emphasizing sub-µA quiescent current, factory-trimmed precision thresholds, and minimal external component count.

FAQ

What is the exact reset threshold voltage of MAX6326XR31+T and how tightly is it specified?

The MAX6326XR31+T has a factory-trimmed nominal reset threshold of 3.08V. At +25°C, this is guaranteed within ±1.5% (3.034V to 3.126V). Over the full operating temperature range of -40°C to +85°C, the threshold remains within ±2.5% (3.003V to 3.150V). This precision eliminates need for external adjustment and ensures consistent brownout detection across environmental conditions.

Does MAX6326XR31+T require any external components to function?

No, MAX6326XR31+T requires zero external components. Its internal precision voltage reference, comparator, and timing capacitor enable full reset supervision functionality with only VCC, GND, and RESET connections. The push-pull output drives standard CMOS reset inputs directly - no pull-up resistor is needed, reducing BOM count and PCB area.

What is the minimum VCC voltage at which MAX6326XR31+T guarantees correct reset state?

MAX6326XR31+T guarantees correct reset assertion and release behavior down to VCC = 1.2V across the full -40°C to +85°C temperature range. This allows the device to maintain supervision during deep brownout or battery depletion scenarios where other reset ICs may fail to assert reliably - critical for safety-critical and energy-harvesting applications.

How does the reset timeout behavior of MAX6326XR31+T ensure reliable microprocessor startup?

MAX6326XR31+T asserts RESET for a minimum of 100ms after VCC rises above the 3.08V threshold. This guaranteed minimum pulse width exceeds JEDEC JESD82 requirements for most microprocessors and ensures sufficient time for clock stabilization, PLL lock, memory initialization, and peripheral power-rail settling before the host processor exits reset - preventing boot failures.

Is MAX6326XR31+T pin-compatible with other common reset ICs?

Yes, MAX6326XR31+T is pin-compatible with the industry-standard MAX803/MAX809/MAX810 family in SC70-3 and SOT23-3 packages. Pin 1 = GND, Pin 2 = RESET (active-low push-pull), Pin 3 = VCC. This allows drop-in replacement in existing designs using those parts, provided the 3.08V threshold and 1µA supply current meet system requirements.